CN111096037A

CN111096037A - Method of transmitting and receiving downlink data and apparatus therefor

Info

Publication number: CN111096037A
Application number: CN201980004541.2A
Authority: CN
Inventors: 郭圭环; 李承旻; 李润贞; 李贤镐
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2018-04-27
Filing date: 2019-04-29
Publication date: 2020-05-01
Anticipated expiration: 2039-04-29
Also published as: US20220094507A1; CN111096037B; US10623169B2; TW201946406A; US11743015B2; KR20190125227A; KR20200123055A; WO2019209084A1; KR102088025B1; US20200119891A1; TWI704791B; JP7141469B2; US20190334689A1; US11251927B2; JP2021519026A; EP3648535A1; US11139943B2; US20200119892A1; KR102284376B1; KR20200028368A

Abstract

Disclosed is a method for receiving downlink data by a terminal in a wireless communication system. Specifically, the method comprises the following steps: receiving information on a number of repetitions of downlink data repeatedly transmitted in at least one first Transmission Time Interval (TTI) included in a first subframe and at least one second TTI included in a second subframe; and receiving downlink data based on the number of repetitions, wherein when a transmission pattern of the first subframe and a transmission pattern of the second subframe are different, the downlink data is not received in the at least one second TTI, and the second subframe is located after the first subframe.

Description

Method of transmitting and receiving downlink data and apparatus therefor

Technical Field

The present disclosure relates to a method of transmitting and receiving downlink data and an apparatus therefor, and more particularly, to a method of transmitting and receiving repeatedly transmitted data in consecutive subframes when the consecutive subframes are configured to different subframe types and/or different transmission patterns and an apparatus therefor.

Background

A brief description will be given of a third generation partnership project long term evolution (3GPP LTE) system as an example of a wireless communication system to which the present invention can be applied.

Fig. 1 shows a configuration of an evolved universal mobile telecommunications system (E-UMTS) network as an exemplary wireless communication system. The E-UMTS system is an evolution of the conventional UMTS system, and 3GPP works on the basis of the E-UMTS standardization. E-UMTS is also known as an LTE system. For details of the technical specifications of UMTS and E-UMTS, refer to "3 rd Generation Partnership Project, respectively; version 7 and version 8 of Technical Specification Group Radio Access Network ".

Referring to fig. 1, the E-UMTS system includes a User Equipment (UE), an evolved node B (eNode B or eNB), and an Access Gateway (AG) located at one end of an evolved UMTS terrestrial radio access network (E-UTRAN) and connected to an external network. The eNB may transmit multiple data streams simultaneously for broadcast services, multicast services, and/or unicast services.

A single eNB manages one or more cells. The cell is set to operate in one of bandwidths of 1.25Mhz, 2.5Mhz, 5Mhz, 10Mhz, 15Mhz, and 20Mhz, and provides a Downlink (DL) or Uplink (UL) transmission service to a plurality of UEs in the bandwidth. Different cells may be configured to provide different bandwidths. The eNB controls data transmission to and reception from a plurality of UEs. Regarding DL data, the eNB notifies a specific UE of a time-frequency region in which DL data should be transmitted, a coding scheme, a data size, hybrid automatic repeat request (HARQ) information, and the like, by transmitting DL scheduling information to the UE. Regarding UL data, the eNB informs a specific UE of a time-frequency region in which the UE can transmit data, a coding scheme, a data size, HARQ information, and the like, by transmitting UL scheduling information to the UE. An interface for transmitting user traffic or control traffic may be defined between enbs. The Core Network (CN) may include AG and network nodes for user registration of the UE. The AG manages mobility of the UE on a Tracking Area (TA) basis. The TA includes a plurality of cells.

Although the development stage of wireless communication technology has reached LTE based on Wideband Code Division Multiple Access (WCDMA), the demands and expectations of users and service providers are increasing. Considering that other radio access technologies are being developed, new technologies evolution is required to achieve future competitiveness. In particular, cost reduction per bit, increased service availability, flexible use of frequency bands, simplified structure, open interfaces, appropriate power consumption of the UE, and the like are required.

Disclosure of Invention

Technical problem

An object of the present disclosure is to provide a method of transmitting and receiving a DL data channel and an apparatus thereof.

Technical objects that can be achieved by the present disclosure are not limited to those specifically described above, and other technical objects not described herein will be more clearly understood by those skilled in the art from the following detailed description.

Technical scheme

To achieve these objects and other advantages and in accordance with the purpose of the present disclosure, as embodied and broadly described herein, a method of receiving Downlink (DL) data by a User Equipment (UE) in a wireless communication system includes: receiving information on a number of repetitions of DL data repeatedly transmitted in at least one first Transmission Time Interval (TTI) included in a first subframe and at least one second TTI included in a second subframe; and receiving DL data based on the number of repetitions. Not receiving the DL data in the at least one second TTI when a Transmission Mode (TM) of a first subframe is different from a TM of a second subframe. The second subframe is located after the first subframe.

The first subframe and the second subframe may be consecutive.

The number of repetitions may exceed 1.

Any one of the first subframe and the second subframe may be a Multicast Broadcast Single Frequency Network (MBSFN) subframe, and the other one of the first subframe and the second subframe may be a non-MBSFN subframe.

A Common Reference Signal (CRS) -based TM may be configured for any one of the first and second subframes, and a demodulation reference signal (DMRS) -based TM may be configured for the other one of the first and second subframes.

Information on the number of repetitions of DL data may be included in Downlink Control Information (DCI) based on a cell-radio network temporary identifier (C-RNTI).

The at least one first TTI and the at least one second TTI may be short TTIs.

In another aspect of the present disclosure, an apparatus for receiving Downlink (DL) data in a wireless communication system includes a memory and at least one processor coupled to the memory. The at least one processor is configured to: receiving information on a number of repetitions of DL data repeatedly transmitted in at least one first Transmission Time Interval (TTI) included in a first subframe and at least one second TTI included in a second subframe; and receiving DL data based on the number of repetitions. Receiving no DL data in the at least one second TTI when a Transmission Mode (TM) of the first subframe is different from a TM of the second subframe. The second subframe is located after the first subframe.

The first subframe and the second subframe may be consecutive.

The number of repetitions may exceed 1.

The at least one first TTI and the at least one second TTI may be short TTIs.

In another aspect of the present disclosure, a method of transmitting Downlink (DL) data by a Base Station (BS) in a wireless communication system includes: transmitting information on a number of repetitions of DL data repeatedly transmitted in at least one first Transmission Time Interval (TTI) included in a first subframe and at least one second TTI included in a second subframe; and transmitting DL data based on the repetition number. Transmitting no DL data in the at least one second TTI when a Transmission Mode (TM) of the first subframe is different from a TM of the second subframe. The second subframe is located after the first subframe.

In another aspect of the present disclosure, a User Equipment (UE) for receiving Downlink (DL) data in a wireless communication system includes a transceiver and at least one processor coupled to the transceiver. The at least one processor is configured to: the method includes controlling a transceiver to receive information on a number of repetitions of DL data repeatedly transmitted in at least one first Transmission Time Interval (TTI) included in a first subframe and at least one second TTI included in a second subframe, and controlling the transceiver to receive the DL data based on the number of repetitions. Receiving no DL data in the at least one second TTI when a Transmission Mode (TM) of the first subframe is different from a TM of the second subframe. The second subframe is located after the first subframe.

In another aspect of the present disclosure, a Base Station (BS) for transmitting Downlink (DL) data in a wireless communication system includes a transceiver and at least one processor coupled to the transceiver. The at least one processor is configured to: the method includes controlling a transceiver to transmit information on a number of repetitions of DL data repeatedly transmitted in at least one first Transmission Time Interval (TTI) included in a first subframe and at least one second TTI included in a second subframe, and controlling the transceiver to transmit the DL data based on the number of repetitions. Transmitting no DL data in the at least one second TTI when a Transmission Mode (TM) of the first subframe is different from a TM of the second subframe. The second subframe is located after the first subframe.

Advantageous effects

According to the present disclosure, data repeatedly transmitted in subframes configured with different subframe types and/or different TMs may be efficiently transmitted and received.

Those skilled in the art will appreciate that the effects achievable by the present disclosure are not limited to those specifically described above, and other advantages of the present disclosure will be more clearly understood from the detailed description made above in conjunction with the accompanying drawings.

Drawings

Fig. 1 shows a configuration of an evolved universal mobile telecommunications system (E-UMTS) network as an example of a wireless communication system.

Figure 2 illustrates a control plane protocol stack and a user plane protocol stack in a radio interface protocol architecture that conforms to the third generation partnership project (3GPP) radio access network standard between a User Equipment (UE) and an evolved UMTS terrestrial radio access network (E-UTRAN).

Fig. 3 illustrates physical channels in a 3GPP system and a general signal transmission method using the same.

Fig. 4 illustrates a structure of a radio frame in a Long Term Evolution (LTE) system.

Fig. 5 shows a structure of a downlink radio frame in the LTE system.

Fig. 6 illustrates a resource unit for configuring a downlink control channel in an LTE system.

Fig. 7 illustrates a structure of an uplink subframe in an LTE system.

Fig. 8 is a diagram illustrating a structure of a Multimedia Broadcast Single Frequency Network (MBSFN) subframe.

Fig. 9 is a diagram illustrating a structure of a short Transmission Time Interval (TTI).

Fig. 10 is a diagram showing an example of scheduled repeatedly transmitted data.

Fig. 11 to 13 are diagrams illustrating operations of a UE, a BS, and a network according to the present disclosure.

Fig. 14 is a diagram illustrating an example of data repeatedly transmitted in subframes configured with different TM and/or types.

Fig. 15 is a block diagram of a wireless device for implementing the present disclosure.

Detailed Description

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

The configuration, operation, and other features of the present disclosure will be readily understood by the embodiments of the present disclosure described with reference to the accompanying drawings. The embodiments of the present disclosure set forth herein are examples in which technical features of the present disclosure are applied to a third generation partnership project (3GPP) system.

Although embodiments of the present disclosure are described in the context of Long Term Evolution (LTE) systems and LTE-Advanced (LTE-a) systems, they are purely exemplary. Therefore, the embodiments of the present disclosure are applicable to any other communication system as long as the above definition is valid for the communication system. In addition, although embodiments of the present disclosure are described in the context of Frequency Division Duplexing (FDD), they are also readily applicable to half FDD (H-FDD) or Time Division Duplexing (TDD) with some modifications.

Figure 2 illustrates a control plane protocol stack and a user plane protocol stack in a radio interface protocol architecture conforming to a 3GPP radio access network standard between a User Equipment (UE) and an evolved UMTS terrestrial radio access network (E-UTRAN). The control plane is a path where the UE and the E-UTRAN transmit control messages to manage a call, and the user plane is a path where data (e.g., voice data or internet packet data) generated from an application layer is transmitted.

The Physical (PHY) layer at layer 1(L1) provides information transfer services to its higher layers (medium access control (MAC) layer). The PHY layer is connected to the MAC layer via a transport channel. The transport channel passes data between the MAC layer and the PHY layer. Data is transmitted on a physical channel between the PHY layers of the transmitter and receiver. The physical channel uses time and frequency as radio resources. Specifically, the physical channel is modulated by Orthogonal Frequency Division Multiple Access (OFDMA) for the Downlink (DL) and single carrier frequency division multiple access (SC-FDMA) for the Uplink (UL).

The MAC layer at layer 2(L2) provides services to its higher layers (radio link control (RLC) layer) via logical channels. The RLC layer at L2 supports reliable data transmission. The RLC function may be implemented in a functional block of the MAC layer. A Packet Data Convergence Protocol (PDCP) layer at L2 performs header compression to reduce the amount of unnecessary control information, and thus efficiently transmits Internet Protocol (IP) packets such as IP version 4(IPv4) or IP version 6(IPv6) packets via an air interface having a narrow bandwidth.

The Radio Resource Control (RRC) layer at the lowest part of layer 3 (or L3) is defined only on the control plane. The RRC layer controls logical channels, transport channels, and physical channels related to configuration, reconfiguration, and release of radio bearers. The radio bearer refers to a service provided at L2 for data transmission between the UE and the E-UTRAN. For this purpose, the RRC layers of the UE and the E-UTRAN exchange RRC messages with each other. If an RRC connection is established between the UE and the E-UTRAN, the UE is in an RRC connected mode, otherwise, the UE is in an RRC idle mode. A non-access stratum (NAS) layer above the RRC layer performs functions including session management and mobility management.

DL transport channels for transmitting data from the E-UTRAN to the UE include a Broadcast Channel (BCH) carrying system information, a Paging Channel (PCH) carrying paging messages, and a Shared Channel (SCH) carrying user traffic or control messages. DL multicast traffic or control messages or DL broadcast traffic or control messages may be transmitted on the DL SCH or a separately defined DL Multicast Channel (MCH). The UL transport channels for transmitting data from the UE to the E-UTRAN include a Random Access Channel (RACH) carrying an initial control message and an UL SCH carrying user traffic or control messages. Logical channels defined above and mapped to the transport channels include a Broadcast Control Channel (BCCH), a Paging Control Channel (PCCH), a Common Control Channel (CCCH), a Multicast Control Channel (MCCH), a Multicast Traffic Channel (MTCH), etc.

Fig. 3 illustrates physical channels in a 3GPP system and a general method of transmitting signals on the physical channels.

Referring to fig. 3, when a UE is powered on or enters a new cell, the UE performs an initial cell search (S301). Initial cell search involves acquiring synchronization with the eNB. Specifically, by receiving a primary synchronization channel (P-SCH) and a secondary synchronization channel (S-SCH) from the eNB, the UE synchronizes its timing to the eNB and acquires a cell Identifier (ID) and other information. The UE may then acquire the information broadcast in the cell by receiving a Physical Broadcast Channel (PBCH) from the eNB. During initial cell search, the UE may monitor a DL channel state by receiving a downlink reference signal (DLRS).

After the initial cell search, the UE may acquire detailed system information by receiving a Physical Downlink Control Channel (PDCCH) and receiving a Physical Downlink Shared Channel (PDSCH) based on information included in the PDCCH (S302).

If the UE initially accesses the eNB or has no radio resources for signaling to the eNB, the UE may perform a random access procedure with the eNB (S303 to S306). In the random access procedure, the UE may transmit a predetermined sequence as a preamble on a Physical Random Access Channel (PRACH) (S303 and S305), and may receive a response message to the preamble on the PDCCH and a PDSCH associated with the PDCCH (S304 and S306). In case of the contention-based RACH, the UE may additionally perform a contention resolution procedure.

After the above procedure, the UE may receive a PDCCH and/or a PDSCH from the eNB (S307) and transmit a Physical Uplink Shared Channel (PUSCH) and/or a Physical Uplink Control Channel (PUCCH) to the eNB (S308), which is a general DL and UL signal transmission procedure. Specifically, the UE receives Downlink Control Information (DCI) on the PDCCH. Here, the DCI includes control information (e.g., resource allocation information for the UE). Different DCI formats are defined according to different uses of DCI.

The control information transmitted by the UE to the eNB on the UL or received from the eNB on the DL includes DL/UL acknowledgement/negative acknowledgement (ACK/NACK) signals, Channel Quality Indicators (CQIs), Precoding Matrix Indexes (PMIs), Rank Indicators (RIs), and the like. In a 3gpp lte system, a UE may send control information (e.g., CQI, PMI, RI, etc.) on the PUSCH and/or PUCCH.

Fig. 4 shows a structure of a radio frame used in the LTE system.

Referring to FIG. 4, the radio frame is 10ms (327200 xT)_s) Long and divided into 10 equally sized subframes. Each subframe is 1ms long and is further divided into two slots. Each time slot is 0.5ms (15360 xT)_s) Long. Here, T_sRepresents a sampling time, and T_s＝l/(15kHzx2048)＝3.2552x10^-8(about 33 ns). The slot includes a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols or SC-FDMA symbols in the time domain multiplied by a plurality of Resource Blocks (RBs) in the frequency domain. In the LTE system, one RB includes 12 subcarriers by 7 (or 6) OFDM symbols. A unit time for transmitting data is defined as a Transmission Time Interval (TTI). The TTI may be defined in units of one or more subframes. The above radio frame structure is purely exemplary, and thus the number of subframes in a radio frame, the number of slots in a subframe, or the number of OFDM symbols in a slot may vary.

Fig. 5 illustrates an exemplary control channel included in a control region of a subframe in a DL radio frame.

Referring to fig. 5, a subframe includes 14 OFDM symbols. According to the subframe configuration, the first to three OFDM symbols of the subframe are used for the control region, and the other 13 to 11 OFDM symbols are used for the data region. In fig. 5, reference numerals R1 to R4 denote RSs or pilot signals for antenna 0 to antenna 3. The RS is allocated in a predetermined pattern in a subframe regardless of the control region and the data region. A control channel is allocated to non-RS resources in the control region, and a traffic channel is also allocated to non-RS resources in the data region. The control channels allocated to the control region include a Physical Control Format Indicator Channel (PCFICH), a physical hybrid ARQ indicator channel (PHICH), a Physical Downlink Control Channel (PDCCH), and the like.

The PCFICH is a physical control format indicator channel carrying information on the number of OFDM symbols used for the PDCCH in each subframe. The PCFICH is located in the first OFDM symbol of the subframe and is configured with a higher priority than the PHICH and PDCCH. The PCFICH includes 4 Resource Element Groups (REGs), and each REG is allocated to a control region based on a cell Identity (ID). One REG includes 4 Resource Elements (REs). The RE is a minimum physical resource defined by one subcarrier multiplied by one OFDM symbol. The PCFICH is set to 1 to 3 or 2 to 4 according to the bandwidth. The PCFICH is modulated according to Quadrature Phase Shift Keying (QPSK).

The PHICH is a physical automatic repeat request (HARQ) indicator channel that carries a hybrid HARQ ACK/NACK for UL transmissions. That is, the PHICH is a channel that transmits DL ACK/NACK information for UL HARQ. The PHICH includes one REG and is scrambled in a cell-specific manner. The ACK/NACK is indicated in one bit and modulated according to Binary Phase Shift Keying (BPSK). The modulated ACK/NACK is spread with a Spreading Factor (SF) of 2 or 4. A plurality of PHICHs mapped to the same resource form a PHICH group. The number of PHICHs multiplexed to the PHICH group is determined according to the number of spreading codes. PHICH (group) is repeated three times to obtain diversity gain in frequency and/or time domain.

The PDCCH is a physical DL control channel allocated to the first n OFDM symbols of the subframe. Here, n is an integer of 1 or more indicated by PCFICH. The PDCCH occupies one or more CCEs. The PDCCH carries resource allocation information on a transport channel, PCH and DL-SCH, UL scheduling grant, and HARQ information to each UE or UE group. The PCH and DL-SCH are transmitted on the PDSCH. Therefore, the eNB and the UE generally transmit and receive data on the PDSCH except for specific control information or specific service data.

Information indicating that one or more UEs receive PDSCH data and information indicating how the UEs should receive and decode PDSCH data is transmitted on the PDCCH. For example, assuming that a Cyclic Redundancy Check (CRC) of a specific PDCCH is masked by a Radio Network Temporary Identity (RNTI) "a" and information on data transmitted in a radio resource (e.g., in a frequency location) "B" based on transport format information (e.g., transport block size, modulation scheme, coding information, etc.) "C" is transmitted in a specific subframe, UEs within a cell use their RNTI information to monitor (i.e., blind decode) the PDCCH in a search space. If one or more UEs have RNTI "a", the UEs receive a PDCCH and receive a PDSCH indicated by "B" and "C" based on information of the received PDCCH.

Fig. 6 shows resource elements used to configure a downlink control channel in LTE. Fig. 6 (a) shows a case where the number of transmission (Tx) antennas is 1 or 2, and fig. 6 (b) shows a case where the number of Tx antennas is 4. Although different RS patterns are used according to the number of Tx antennas, REs are configured in the same manner for DL control channels.

Referring to fig. 6, a basic resource unit of a DL control channel is an REG. The REG includes four contiguous REs except for the RE carrying the RS. REGs are marked with bold lines in fig. 6. The PCFICH and PHICH include 4 REGs and 3 REGs, respectively. The PDCCH is configured in units of Control Channel Elements (CCEs), and each CCE includes 9 REGs.

To determine whether a PDCCH comprising L CCEs is transmitted to a UE, the UE is configured to monitor M contiguously or arranged according to a predetermined rule^(L)(≧ L) CCEs. The L that the UE should consider for PDCCH reception may be a complex value. The set of CCEs that the UE should monitor to receive the PDCCH is called the search space. For example, LTE defines a search space as shown in table 1.

TABLE 1

In table 1, L is a CCE aggregation level (i.e., the number of CCEs in PDCCH), S_k ^(L)Is a search space with a CCE aggregation level L, M^(L)Is the number of PDCCH candidates to be monitored in the search space with CCE aggregation level L.

The search space is classified into a UE-specific search space accessible only by a specific UE and a common search space accessible by all UEs within the cell. The UE monitors the common search space with

CCE aggregation levels

4 and 8 and the UE-specific search space with

CCE aggregation levels

1, 2, 4 and 8. The common search space and the UE-specific search space may overlap each other.

The location of the first CCE (CCE having the smallest index) of the PDCCH search space allocated to the UE varies per subframe for each CCE aggregation level. This is referred to as PDCCH search space hashing.

CCEs may be distributed across the system band. More specifically, a plurality of logically contiguous CCEs may be input to the interleaver and the interleaver may arrange the sequence of the input CCEs based on REGs. Thus, the time/frequency resources of one CCE are physically distributed across the total time/frequency region of the control region of the subframe. Since the control channel is configured in CCE units but interleaved in REG units, the frequency diversity gain and the interference randomization gain can be maximized.

Fig. 7 shows a structure of a UL subframe in the LTE system.

Referring to fig. 7, the UL subframe may be divided into a control region and a data region. A Physical Uplink Control Channel (PUCCH) including Uplink Control Information (UCI) is allocated to the control region, and a Physical Uplink Shared Channel (PUSCH) including user data is allocated to the data region. The middle of the subframe is allocated to the PUSCH, and both sides of the data region are allocated to the PUCCH in the frequency domain. The control information transmitted on the PUCCH may include HARQ ACK/NACK, CQI indicating a downlink channel state, RI for Multiple Input Multiple Output (MIMO), and Scheduling Request (SR) requesting UL resource allocation. The PUCCH for one UE occupies one RB in each slot of the subframe. That is, two RBs allocated to the PUCCH are frequency hopped on a slot boundary of the subframe. Specifically, PUCCHs of m-0, m-1, and m-2 are allocated to the subframes in fig. 7.

Referring to the upper part of fig. 8, 10 subframes included in one frame may include non-MBSFN subframes for normal data transmission and reception and MBSFN subframes that may be used for broadcast or multicast data transmission. The non-MBSFN subframe and the MBSFN subframe differ in the number of OFDM symbols, the length of a Cyclic Prefix (CP), and the structure and number of cell-specific reference signals (CRS). In legacy LTE-Rel 8 and LTE-Rel 9 systems, MBSFN subframes are only used for the purpose of transmitting broadcast or multicast data.

However, in LTE-Rel 10 or later systems, MBSFN subframes may be used for unicast data transmission (for UE-specific data transmission) as well as for the purpose of broadcast or multicast data transmission.

Referring to the lower part of fig. 8, the MBSFN subframe is a subframe for transmitting a physical multicast channel (PBCH), and may indicate a subframe in which CRS is not transmitted in a region other than a PDCCH region including the first two OFDM symbols. In this case, the PDCCH region may include one OFDM symbol. A UE that is not configured for data reception in an MBSFN subframe may not receive DL data in a region other than the PDCCH region included in the MBSFN subframe. The MBSFN configuration information may represent information for configuring an MBSFN subframe, and may be transmitted through a higher layer signal. For example, a Base Station (BS) may transmit MBSFN configuration information through system information block 2(SIB-2) transmitted on PDSCH. The MBSFN configuration information may include information such as a bitmap indicating MBSFN subframes, a radio frame allocation period, a radio frame allocation offset, and subframe allocation.

Now, a method of transmitting and receiving a DL data channel according to the present disclosure will be described.

In transmitting and receiving information in the next generation communication system, a method of achieving very low delay and very high reliability is being considered. To this end, a method of configuring various target quality of service (QoS) requirements such as delay and/or reliability and efficiently providing a service satisfying the target QoS requirements by differently performing operations according to the respective target QoS requirements is considered.

The present disclosure proposes a method of repeatedly transmitting DL data by a BS to a UE in order to achieve higher reliability and lower delay in a cellular communication system. In particular, the present disclosure proposes a method of repeatedly transmitting DL data when repeated transmission of DL data is scheduled to span different types of subframes.

While the statements and/or embodiments of the disclosure may be viewed as one set forth aspect, combinations of the statements and/or embodiments may also be viewed as new aspects. In addition, particular statements of invention are not limited to implementations set forth in this disclosure, but rather are not limited to application to particular systems. That is, the specific inventive statement may be extended within a range that a person skilled in the art can easily derive from the embodiments presented in the present disclosure, and the embodiments of the present disclosure are applicable to various communication systems such as LTE, LTE-A, LTE-Pro, NR, and IEEE systems.

In addition, all parameters of the present disclosure, all operations of the present disclosure, respective parameters and/or combinations of respective operations, whether to apply the corresponding parameters and/or operations, and/or whether to apply the respective parameters and/or combinations of respective operations may be indicated to the UE by the BS through higher layer signaling and/or physical layer signaling, or may be predefined in the system.

The disclosure described with respect to different subframe types may also be applied to different Transmission Modes (TM). For example, the disclosure may be applied even when different TMs are configured in two subframes having the same subframe type. It is apparent that the Transmission Time Interval (TTI) described in the present disclosure may correspond to various TTI length units such as subslots/slots/subframes.

Herein, subslots and slots may be referred to as short TTIs. That is, a short TTI may include sub-slots and slots. The short TTI is defined as a length shorter than the length of 1ms of the downlink shared channel (DL-SCH) and the uplink shared channel (UL-SCH). Control channels supporting short TTIs (e.g., short pdcch (spdcch) and short pucch (spucch)) may also be transmitted in a duration shorter than 1 ms. In this case, the slot has a duration of 0.5 and thus may include 7 symbols. A sub-slot may include two symbols or three symbols.

In a TDD system, short TTI-based transmission may be performed in units of slots, and in an FDD system, short TTI-based transmission may be performed in units of slots and/or sub-slots.

In this case, one subframe may include 6 sub-slots, and a pattern in which the sub-slots are disposed may be different according to the number of symbols used for the PDCCH. Specifically, if the number of symbols for the PDCCH is 1 or 3, each of the

sub-slots

0 and 5 includes 3 symbols and each of the other sub-slots includes 2 symbols, as shown in (a) of fig. 9.

If the number of symbols for the PDCCH is 2, each of

sub-slots

1 and 5 includes 3 symbols and each of the other sub-slots includes 2 symbols, as shown in (b) of FIG. 9.

To improve the reliability of DL transmission, data may be repeatedly transmitted. For example, the control channel and the data channel scheduled by the control channel may be independently transmitted in each TTI, as shown in (a) of fig. 10. The BS may inform the UE that data channels transmitted in a plurality of TTIs carry the same Transport Block (TB) using HARQ process numbers or New Data Indicators (NDIs) in respective control channels, and repeatedly transmit the same data in a plurality of TTIs.

To further reduce the overhead of the control channel in (a) of fig. 10, the control channel transmitted in a single TTI may schedule data repeatedly transmitted in multiple TTIs, as shown in (b) of fig. 10. That is, a control channel transmitted in a single TTI may schedule data for multiple TTIs.

Accordingly, the control channel may be transmitted in a plurality of TTIs, and in this case, the number of TTIs in which the control channel is transmitted may be less than the number of TTIs in which the data channel is transmitted. Information such as Modulation and Coding Scheme (MCS)/Resource Allocation (RA) in Downlink Control Information (DCI) for scheduling data repeatedly transmitted in a plurality of TTIs may be equally applied to all TTIs where data is repeatedly transmitted. The DCI may include information on the number of repeated transmissions of data.

In an LTE short tti (stti) system, different TM per subframe type may be configured. In particular, different TMs may be configured for MBSFN subframes and non-MBSFN subframes. For example, TM4 may be configured for non-MBSFN subframes, and TM9 may be configured for MBSFN subframes. A TTI (i.e., sTTI) included in a subframe configured as a specific subframe type may operate based on a TM configured corresponding to the specific subframe type.

If data repeatedly transmitted in a plurality of TTIs including a specific TTI is scheduled by DCI transmitted in the specific TTI as described above, information on the number of repeated transmissions k of the data may be transmitted through the DCI.

If the decoding of the DCI is successful, the UE may be configured not to attempt to decode the DCI in the other (k-1) consecutive (or discontinuous) TTIs in which data is repeatedly transmitted, or may be configured to discard the DCI even if the UE has detected the DCI by attempting to decode the DCI. The DCI not decoded or discarded by the UE may be DCI related to cell-RNTI (C-RNTI) -based data scheduling or DCI related to DL data scheduling. The DCI that the UE has successfully decoded may also be DCI related to C-RNTI based data scheduling or DCI related to DL data scheduling.

If the duration of the repeated transmission of data scheduled by the successfully decoded DCI spans subframes (e.g., MBSFN subframes and non-MBSFN subframes) configuring different types and/or different TMs, a Reference Signal (RS) for data decoding in the subframe in which the successfully decoded DCI is transmitted may not be present in a subframe that includes some or all subsequent repeated transmissions of data and is of a different type than the subframe in which the successfully decoded DCI is transmitted. This may then be problematic because the UE cannot perform decoding on subsequent repeated transmissions of data.

For example, when a subframe in which successfully decoded DCI is transmitted is a non-MBSFN subframe, TM4 is configured in the non-MBSFN subframe, and a Common Reference Signal (CRS) is used, if a subframe including part or all of subsequent repeated transmissions of data is an MBSFN subframe and TM9 is configured in the MBSFN subframe, the CRS is not present in the MBSFN subframe, so that the UE may not be able to decode the data repeatedly transmitted in the MBSFN subframe.

In general, the applied RS may be different according to different subframe types configured in subframes having different subframe types and/or different TMs. If the DCI formats of different TMs configured in the subframes of different types are scheduled are different, the field configuration and/or field information of the DCI format are configured differently.

Accordingly, if data repeatedly transmitted in a TTI including a specific TTI and at least one subsequent TTI is scheduled by DCI transmitted in the specific TTI and the DCI is successfully decoded such that the DCI is not decoded or discarded in the subsequent TTI, the UE may not be able to acquire information (e.g., precoding/rank information) that should be provided for a TM configured according to a changed subframe type despite repeatedly transmitting data via subframes configured differently in type. Therefore, a problem may occur in that: the UE cannot normally decode the partial repeat transmission of a particular TB transmitted in the subsequent subframe.

Accordingly, the present disclosure proposes various embodiments for solving the above-described problems.

Before describing the embodiments, a procedure of an overall operation of the UE and the BS according to an embodiment of the present disclosure will now be described.

Fig. 11 is a diagram illustrating an overall operation of a UE according to an embodiment of the present disclosure. Referring to fig. 11, the UE may receive first information for configuring a type of each subframe and second information for configuring a TM applied to each subframe (S1101). The first information and the second information may be received through higher layer signaling and/or physical layer signaling. Then, the UE decodes DCI related to repeated transmission of data in a specific TTI, specifically, in sTTI (S1103). For a type and TM configured in a subframe including DCI, DCI may include information on the number of repeated transmissions of data and information on MCS, RA, precoding, and rank.

Upon detecting the DCI, the UE may receive repeatedly transmitted data via subframes configured to different types and/or different TMs based on the information included in the DCI, the first information, and the second information (S1105).

A detailed operation method in which the UE receives the repeatedly transmitted data based on the detected DCI, the first information, and the second information may be consistent with an embodiment that will be described later.

Now, a procedure of an operation of the BS according to an embodiment of the present disclosure will be described with reference to fig. 12. Referring to fig. 12, the BS may transmit first information for configuring a type of each subframe and second information for configuring a TM applied to each subframe (S1201). The first information and the second information may be transmitted through higher layer signaling and/or physical layer signaling. Then, the BS may transmit DCI related to repeated transmission of data in a specific TTI, specifically, in an sTTI (S1203). For a type and TM configured in a subframe including DCI, DCI may include information on the number of repeated transmissions of data and information on MCS, RA, precoding, and rank.

In transmitting the DCI, the BS may repeatedly transmit data via subframes configured with different types and/or different TMs based on the information included in the DCI, the first information, and the second information (S1205).

A detailed operation method in which the BS repeatedly transmits data via subframes configured as different types and/or different TMs based on the transmitted DCI, the first information, and the second information may conform to an embodiment that will be described later.

A procedure of the operation of the UE and the BS in terms of the entire network will now be described with reference to fig. 13. The BS may transmit first information for configuring a type of each subframe and second information for configuring a TM applied to each subframe to the UE through higher layer signaling and/or physical layer signaling (S1301). Next, the BS may transmit DCI related to repeated transmission of data to the UE in a specific TTI, specifically, in a specific sTTI (S1303). For a type and TM configured in a subframe including DCI, DCI may include information on the number of repeated transmissions of data and information on MCS, RA, precoding, and rank.

In transmitting the DCI, the BS may repeatedly transmit data via subframes configured with different types and/or different TMs based on the information included in the DCI, the first information, and the second information, and the UE may receive the repeatedly transmitted data based on the DCI, the first information, and the second information (S1305).

In this case, a detailed operation method in which the BS repeatedly transmits data via subframes configured to different types and/or different TMs based on the DCI, the first information, and the second information and the UE receives the repeatedly transmitted data may conform to an embodiment which will be described later.

Now, a detailed embodiment for performing operations of the UE and the BS will be described.

For convenience of description, it is assumed in the embodiments of the present disclosure that the UE decodes DCI indicating the number of repeated transmissions of 4 in TTI # n, TTI # n and TTI # n +1 in which data is repeatedly transmitted are included in a subframe of type a (and/or TM a), and TTI # n +2 and TTI # n +3 in which data is repeatedly transmitted are included in a subframe of type B (and/or TM B), as shown in fig. 14. More specifically, the subframe of type a may be an MBSFN subframe and TM a may be TM 9. In addition, the subframe of type B may be a non-MBSFN subframe and TM B may be TM 4.

However, the above assumptions are made as described above to aid understanding of the present disclosure, and it is apparent that embodiments of the present disclosure and/or the proposed scheme are not limited to the case of the example assumed in fig. 14. In other words, the present disclosure can be widely applied to the case where the number of repeated transmissions, the type of subframe including the repeatedly transmitted TTI (or repeatedly transmitted data), and/or the configuration of the TM are different.

In consideration of the case assumed in fig. 14, the embodiment proposed in the present disclosure will be described.

First, in fig. 14, the BS additionally transmits DCI of TM configured in a subframe of type B in TTI # n +2 and the UE may attempt to decode the additionally transmitted DCI. This may be an exception to the following: if the UE successfully decodes DCI transmitted in a particular TTI for scheduling repeatedly transmitted data, the UE does not attempt to decode DCI transmitted in a subsequent TTI (e.g., DCI related to C-RNTI based data scheduling) or discard the DCI, even if the UE detects the DCI by attempting to perform decoding.

Herein, scheduling information (e.g., precoding/rank) included in the DCI decoded in TTI # n +2 may be equally applied to data transmission in TTI # n +2 and TTI # n + 3. More generally, if successfully decoded DCI is included in different subframes according to a plurality of TTIs to which repeatedly transmitted data of the DCI indicating scheduling belongs and the TM of the different subframes is changed due to a change in subframe type, the UE may additionally detect decoding of the DCI in TTIs included in subsequent subframes having the changed TM and/or type and may attempt to decode the repeatedly transmitted data in subsequent TTIs including the TTI in which the DCI included in the subframe having the changed TM and/or type is detected according to an operation indicated by the DCI. Herein, the TTI of the UE attempting to decode DCI in the subsequent subframe may be the first TTI of the subsequent subframe.

In combination with the partial TM, even if the TM changes according to a corresponding combination while repeatedly transmitting data, the UE may not decode DCI in TTIs included in subsequent subframes. For example, the UE may omit decoding the DCI in the first TTI of the subsequent subframe.

Whether to perform the operation may be predefined in the system or may be indicated to the UE by the BS through higher layer signaling and/or physical layer signaling.

The above operations may be performed such that two DCIs are respectively transmitted in two subframes configured to be different TM and/or different types in a duration of repeatedly transmitting data. In this case, the BS may indicate to the UE that the one or more TTIs corresponding to the number of repeated transmissions of the data indicated by the first DCI may include one or more TTIs corresponding to the number of repeated transmissions of the data indicated by the second DCI.

For example, if DCI transmitted in TTI # n indicates the number of repeated transmission times k of data, data is repeatedly transmitted in TTI # n to TTI # n + (k-1). If a TTI starting from TTI # n + p (where p < k-1) is included in a subframe configured with a TM and/or type different from the TM and/or type of the preceding TTI, DCI may be transmitted in TTI # n + p and the UE may be operable to decode the DCI.

In this case, the number of repeated transmissions of data indicated by the DCI transmitted in TTI # n + p may be a value less than or equal to k-p. Alternatively, assuming that the number of repeated transmissions of data indicated by the DCI transmitted in TTI # n + p is k-p, a specific value predefined or indicated to the UE by the BS through higher layer signaling and/or physical layer signaling may be transmitted in a field indicating the number of repeated transmissions of data in the DCI, and the specific value may be used as a virtual Cyclic Redundancy Check (CRC).

In addition, the BS may indicate the number of repeated transmissions of data in consideration of a boundary between subframes in which TM and/or subframe types are changed or a boundary between subframes having the same TM and/or subframe types. In this case, whether data repeatedly transmitted via a boundary between subframes in which TM and/or subframe types are changed or a boundary between subframes having the same TM and/or subframe types is combined may be predefined in the system or may be indicated to the UE by the BS through higher layer signaling and/or physical layer signaling.

For example, if 4 times of repeated transmission of data is required to be indicated at the timing of TTI # n and the subframe type and/or TM is changed from TTI # n +2, the BS may indicate the number of repeated transmission of data 2 through the DCI transmitted at the timing of TTI # n and the number of repeated transmission of data 2 through the DCI transmitted at the timing of TTI # n +2, and the same HARQ process ID and/or non-handover NDI as those of the previously transmitted DCI. If it is indicated or predefined that data to be repeatedly transmitted via two subframes is to be combined, the UE may combine a total of 4 repeated transmissions (twice per type and/or TM) of data and transmit HARQ-ACKs for the data based on the timing of receiving all data repeatedly transmitted via a subframe boundary.

The BS may predefine scheduling information (e.g., precoding/rank) to be applied to data repeated transmission in TTIs # n +2 and # n +3 of subframes of type B in the system or signal the scheduling information to the UE through higher layer signaling and/or physical layer signaling. In this case, contrary to the above description, additional DCI does not need to be transmitted in TTI # n + 2. For example, if the TM and/or frame type is changed from CRS-based TM and/or non-MBSFN subframes to DMRS-based TM and/or MBSFN subframes, information such as scrambling ID, number of layers, antenna ports, and PDSCH rate matching and quasi-co-location indicator (PQI) may be required. The default state or configuration of information may be predefined in the system or may be indicated to the UE by the BS through higher layer signaling and/or physical layer signaling. Alternatively, DCI received during scheduling of the last DMRS-based TM and/or MBSFN subframe may be reused.

Similarly, precoding information may be needed if the TM and/or subframe type changes from DMRS-based TM and/or MBSFN subframes to CRS-based TM and/or non-MBSFN subframes. Accordingly, the default state of the precoding information may be predefined or may be indicated to the UE by the BS through higher layer signaling and/or physical layer signaling. In addition, information of DCI received during scheduling of the last CRS-based TM and/or non-MBSFN subframe may be reused.

The repeated transmission of a specific TB may be restrictively performed only within a subframe configured as the same type or within a single subframe.

For example, TTIs # n, # n +1, # n +2, and # n +3 performing repeated transmission of data may be located only in the same type of subframe. In other words, the repeated transmission of a specific TB may be performed via subframes having the same type, but may not be performed via subframes having different types. Alternatively, the repeated transmission of a specific TB may be performed only in a single subframe. For example, the UE may expect that the DCI sent in the last TTI in the subframe will indicate that the number of repeated transmissions of data does not exceed 1.

Alternatively, if the BS desires to configure the UE with repeated transmission of a specific TB via a subframe boundary, the BS may configure the same TM and/or the same type for subframes before or after the subframe boundary. In terms of the UE, if duplicate data transmission is configured or indicated, the UE may expect that the respective TM and/or type of subframe performing the duplicate data transmission will not be configured differently, but will be configured equally.

The UE may assume that the TM associated with the detected DCI (i.e., the TM related to the subframe in which the detected DCI is transmitted) and/or the subframe type apply to all TTIs in which data is repeatedly transmitted. In other words, if duplicate data transmission across subframes is indicated, the UE may assume that data is transmitted based on the same TM and/or the same subframe type in all TTIs corresponding to the duplicate data transmission. Alternatively, if the number of times of the repeated data transmission configured according to the DCI crosses a subframe boundary where TM and/or subframe type are changed, the repeated data transmission is performed only up to a subframe before the subframe boundary, and the repeated data transmission may be stopped in a subframe after the subframe boundary. In other words, if the configured duration of repeated data transmission crosses a subframe boundary where TM and/or subframe type changes, data that is interpreted as should be transmitted in a subsequent subframe may be discarded.

In this case, even if the number of repeated transmissions remains, the UE does not perform a data decoding operation in the subsequent subframe since the UE does not expect to receive data in the subsequent subframe. Therefore, the UE does not have to receive additional information for decoding the repeatedly transmitted data in subsequent subframes having changed TM and/or subframe type. Therefore, if the UE decodes the DCI for the repeated transmission once, an exceptional operation of discarding or not decoding other DCI need not be defined. In addition, ambiguity that can be generated due to decoding of data repeatedly transmitted in a subsequent subframe based on DCI received in a previous subframe can be avoided.

If the number of times of repeating data transmission is configured for the UE through the DCI, the number of times of repeating may be counted only for TTIs included in subframes having the same TM and/or the same subframe type as the subframe to which the TTI transmitting the DCI belongs. In other words, when subframes are configured as non-MBSFN subframes, and non-MBSFN subframes in this order, if the number of repeated transmissions configured in the first non-MBSFN subframe exceeds the first non-MBSFN subframe, the number of repeated data transmissions may not be counted in the MBSFN subframe, but may be counted in the subsequent non-MBSFN subframe. That is, if DCI indicating repeated data transmission is detected in a first non-MBSFN subframe, data indicated as being repeatedly transmitted may not be transmitted in an MBSFN subframe and repeated data transmission may continue in a subsequent non-MBSFN subframe.

The BS may indicate to the UE which of the above-described embodiments is applied through higher layer signaling and/or physical layer signaling.

That is, when TM of a subframe and/or subframe type is changed and duplicate data transmission is performed via the subframes, the BS may indicate to the UE through higher layer signaling and/or physical layer signaling whether to stop the duplicate data transmission operation and discard the remaining duplicate transmissions, or whether to count the number of duplicate transmissions only in subframes having the same subframe type and/or the same TM, to skip subframes configured as different subframe types or different TMs and continue duplicate data transmission in subsequent subframes having the same type and/or the same TM while repeatedly transmitting data.

When the repeated transmission of the specific TB is performed and the subframe type is changed from the subframe of type a to the subframe of type B, a combination of one or more of the above embodiments may be restrictively applied, and when the subframe type is changed from type B to type a, an operation according to an additional rule may be performed.

For example, when a subframe type is changed from an MBSFN subframe to a non-MBSFN subframe while performing repeated transmission of a specific TB, an RS (e.g., DMRS) configured in the MBSFN subframe for decoding TM-based data may be transmitted as an exception to repeated data transmission in the non-MBSFN subframe. In other words, TM-related RSs configured in MBSFN subframes may be interpreted as additionally transmitted in non-MBSFN subframes, regardless of the TM configured in the non-MBSFN subframes.

The above-described operation may not be applied to the case where the same TM is configured in a subframe even when the type of the subframe is changed, but may be applied to the case where different TMs are configured per subframe or subframe type.

Alternatively, even when the type and/or TM of the data repeatedly transmitted is changed, the same configuration of the type and/or TM of the previous subframe may be applied while the data is repeatedly transmitted.

For example, if TM and/or subframe type is changed from DMRS-based TM and/or MBSFN subframe to CRS-based TM and/or non-MBSFN subframe while data is repeatedly transmitted, DMRS-based TM may be maintained in TTIs where data is repeatedly transmitted, or DMRS-based TM may be maintained in all non-MBSFN subframes, as an exception. As another example, while data is repeatedly transmitted, if TM and/or subframe type is changed from CRS-based TM and/or non-MBSFN subframes to DMRS-based TM and/or MBSFN subframes, this may be addressed by network scheduling, or the repeatedly transmitted TM may be semi-statically configured separately from the TM of another set of subframes.

Fig. 15 illustrates an example of a radio communication device according to an implementation of the present disclosure.

The wireless communication device shown in fig. 15 may represent a User Equipment (UE) and/or a Base Station (BS) according to implementations of the present disclosure. However, the wireless communication device of fig. 15 is not necessarily limited to a UE and/or BS according to the present disclosure, but may implement various types of devices, such as in-vehicle communication systems or devices, wearable devices, laptop computers, and the like.

In the example of fig. 15, the UE and/or BS according to an implementation of the present disclosure includes at least one processor 10, such as a digital signal processor or microprocessor, a transceiver 35, a power management module 5, an antenna 40, a battery 55, a display 15, a keypad 20, at least one memory 30, a Subscriber Identity Module (SIM) card 25, a speaker 45, a microphone 50, and the like. In addition, the UE and/or the BS may include a single antenna or multiple antennas. The transceiver 35 may also be referred to as an RF module.

The at least one processor 10 may be configured to implement the functions, processes, and/or methods described in fig. 1-14. In at least some implementations described in fig. 1-14, at least one processor 10 may implement one or more protocols, such as layers (e.g., functional layers) of an air interface protocol.

The at least one memory 30 is connected to the at least one processor 10 and stores information related to the operation of the at least one processor 10. The at least one memory 30 may be internal or external to the at least one processor 10 and may be coupled to the at least one processor 10 via various techniques, such as wired or wireless communication.

The user may enter various types of information (e.g., instructional information such as a telephone number) through various techniques, such as pressing a button on the keypad 20 or using the microphone 50 to enable speech. At least one processor 10 performs appropriate functions such as receiving and/or processing information from a user and dialing a telephone number.

Data (e.g., operational data) may also be retrieved from the SIM card 25 or the at least one memory 30 to perform the appropriate functions. In addition, the at least one processor 10 may receive and process GPS information from the GPS chip to obtain location information (e.g., vehicle navigation, map service, etc.) of the UE and/or the BS, or perform functions related to the location information. In addition, at least one processor 10 may display these various types of information and data on a display 15 for user reference and convenience.

The transceiver 35 is coupled to the at least one processor 10 to transmit and/or receive radio signals (e.g., RF signals). At this time, at least one processor 10 may control the transceiver 35 to initiate communication and transmit wireless signals including various types of information or data (e.g., voice communication data). The transceiver 35 may include a receiver for receiving radio signals and a transmitter for transmitting. The antenna 40 facilitates the transmission and reception of radio signals. In some implementations, upon receiving a radio signal, transceiver 35 may forward and convert the signal to a baseband frequency for processing by at least one processor 10. The processed signals may be processed (e.g., converted to audible or readable information) according to various techniques and may be output via speaker 45.

In some implementations, the sensors may also be coupled to at least one processor 10. The sensors may include one or more sensing devices configured to detect various types of information, including velocity, acceleration, light, vibration, and the like. At least one processor 10 receives and processes sensor information (e.g., proximity, location, images, etc.) obtained from the sensors to perform various functions such as collision avoidance and autonomous driving.

In addition, various components such as a camera, a USB port, etc., may also be included in the UE and/or the BS. For example, the camera may be further connected to at least one processor 10, which may be used for various services such as autonomous navigation, vehicle safety services, and the like.

Fig. 15 illustrates only one example of an apparatus constituting a UE and/or a BS, and the present disclosure is not limited thereto. For example, in some implementations, some components such as the keypad 20, Global Positioning System (GPS) chip, sensors, speaker 45, and/or microphone 50 may be excluded for UE and/or BS implementations.

Specifically, in order to implement the embodiments of the present disclosure, an operation when the radio communication apparatus shown in fig. 15 is a UE according to the embodiments of the present disclosure will now be described. When the radio communication apparatus is a UE according to an embodiment of the present disclosure, the processor 10 may control the transceiver 35 to receive first information for configuring a type of a subframe and second information for configuring a TM applied to the subframe through higher layer signaling and/or physical layer signaling. Next, the processor 10 decodes DCI related to repeated transmission of data in a specific TTI (specifically, in sTTI). For a type and TM configured in a subframe including DCI, DCI may include information on the number of repeated transmissions of data and information on MCS, RA, precoding, and rank.

Upon detecting DCI, the processor 10 may control the transceiver 35 to receive data repeatedly transmitted via subframes configured to different types and/or different TMs based on information included in DCI, the first information, and the second information.

A detailed operation method of the processor receiving data repeatedly transmitted via the subframe based on the detected DCI, the first information, and the second information may conform to the embodiments described with reference to fig. 1 to 14.

In order to implement the embodiment of the present disclosure, when the radio communication apparatus shown in fig. 15 is a BS according to the embodiment of the present disclosure, the processor 10 may control the transceiver 35 to transmit first information for configuring the type of the subframe and second information for configuring a TM applied to the subframe through higher layer signaling and/or physical layer signaling. Next, the processor 10 controls the transceiver 35 to transmit DCI related to repeated transmission of data in a specific TTI (specifically, in sTTI). For a type and TM configured in a subframe including DCI, DCI may include information on the number of repeated transmissions of data and information on MCS, RA, precoding, and rank.

The processor 10 for controlling transmission of DCI may control the transceiver 35 to transmit repeatedly transmitted data in subframes configured to different types and/or different TMs based on the information included in the DCI, the first information, and the second information.

A detailed operation method of the BS transmitting repeatedly transmitted data in subframes configured to different types and different TMs based on the transmitted DCI, the first information and the second information may conform to the embodiments described with reference to fig. 1 to 14.

The above-described implementations are implementations in which elements and features of the present disclosure are combined in predetermined forms. Individual components or features are to be considered optional unless explicitly stated otherwise. Individual components or features may be implemented without being combined with other components or features. Implementations of the present disclosure may also be constructed by combining some elements and/or features. The order of operations described in the implementations of the present disclosure may be changed. Some configurations or features of a particular implementation may be included in other implementations or may be replaced by corresponding configurations or features of other implementations. It is expressly intended that claims not explicitly recited in a claim may be combined to form an implementation or included in a new claim by amendment after the application.

In some cases, certain operations described herein as being performed by a BS may be performed by its superordinate node. That is, it is apparent that various operations performed for communication with a UE in a network including a plurality of network nodes (including a BS) may be performed by the BS or by a network node other than the BS. The BS may be replaced by terms such as fixed station, node B, eNode B (eNB), access point, and the like.

Implementations consistent with the present disclosure may be implemented by various means, such as hardware, firmware, software, or combinations thereof. In the case of a hardware implementation, implementations of the disclosure may include one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), field programmable gate arrays, processors, controllers, micro-controllers, microprocessors, and the like.

In the case of a firmware or software implementation, the implementation of the present disclosure may be implemented in the form of a module, a procedure, a function, etc. for performing the above-described functions or operations. The software codes may be stored in memory units and driven by processors. The memory unit may be located inside or outside the processor, and may exchange data with the processor through various well-known means.

It will be apparent to those skilled in the art that the present disclosure may be embodied in other specific forms without departing from the spirit of the disclosure. The above description is, therefore, not to be construed in a limiting sense, but rather as an illustration in all aspects. The scope of the disclosure should be determined by reasonable interpretation of the appended claims and all changes which come within the equivalent scope of the disclosure are intended to be embraced therein.

Industrial applicability

Although the above-described method of transmitting and receiving a DL data channel and apparatus thereof are described focusing on an example applied to a 3GPP LTE system, the present disclosure is applicable to various wireless communication systems in addition to the 3GPP LTE system.

Claims

1. A method of receiving downlink, DL, data by a user equipment, UE, in a wireless communication system, the method comprising:

receiving information on a number of repetitions of the DL data repeatedly transmitted in at least one first Transmission Time Interval (TTI) included in a first subframe and at least one second TTI included in a second subframe; and

receiving the DL data based on the number of repetitions,

wherein the DL data is not received in the at least one second TTI when the Transmission Mode (TM) of the first subframe is different from the TM of the second subframe, and

the second subframe is located after the first subframe.

2. The method of claim 1, wherein the first subframe and the second subframe are consecutive.

3. The method of claim 1, wherein the number of repetitions exceeds 1.

4. The method of claim 1, wherein either of the first subframe and the second subframe is a Multicast Broadcast Single Frequency Network (MBSFN) subframe and the other of the first subframe and the second subframe is a non-MBSFN subframe.

5. The method of claim 1, wherein a TM based on a common reference signal, CRS, is configured for any one of the first and second subframes and a TM based on a demodulation reference signal, DMRS, is configured for the other one of the first and second subframes.

6. The method of claim 1, wherein the information related to the number of repetitions of the DL data is included in downlink control information, DCI, based on a cell-radio network temporary identifier, C-RNTI.

7. The method of claim 1, wherein the at least one first TTI and the at least one second TTI are short TTIs.

8. An apparatus for receiving Downlink (DL) data in a wireless communication system, the apparatus comprising:

a memory; and

at least one processor coupled to the memory,

wherein the at least one processor is configured to:

receiving information on a number of repetitions of the DL data repeatedly transmitted in at least one first Transmission Time Interval (TTI) included in a first subframe and at least one second TTI included in a second subframe; and is

Receiving the DL data based on the number of repetitions, and

the second subframe is located after the first subframe.

9. The device of claim 8, wherein the first subframe and the second subframe are consecutive.

10. The apparatus of claim 8, wherein the number of repetitions exceeds 1.

11. The device of claim 8, wherein any of the first and second subframes is a Multicast Broadcast Single Frequency Network (MBSFN) subframe and the other of the first and second subframes is a non-MBSFN subframe.

12. The device of claim 8, wherein a TM based on a common reference signal, CRS, is configured for any one of the first and second subframes and a TM based on a demodulation reference signal, DMRS, is configured for the other one of the first and second subframes.

13. The apparatus of claim 8, wherein the information on the number of repetitions of the DL data is included in downlink control information, DCI, based on a cell-radio network temporary identifier, C-RNTI.

14. The device of claim 8, wherein the at least one first TTI and the at least one second TTI are short TTIs.

15. A method for transmitting downlink, DL, data by a base station, BS, in a wireless communication system, the method comprising the steps of:

transmitting information on a number of repetitions of the DL data repeatedly transmitted in at least one first Transmission Time Interval (TTI) included in a first subframe and at least one second TTI included in a second subframe; and

transmitting the DL data based on the number of repetitions,

wherein when the Transmission Mode (TM) of the first subframe is different from the TM of the second subframe, the DL data is not transmitted in the at least one second TTI, and

the second subframe is located after the first subframe.

16. A user equipment, UE, for receiving downlink, DL, data in a wireless communication system, the UE comprising:

a transceiver; and

at least one processor coupled to the transceiver,

wherein the at least one processor is configured to:

control the transceiver to receive information on a number of repetitions of the DL data repeatedly transmitted in at least one first Transmission Time Interval (TTI) included in a first subframe and at least one second TTI included in a second subframe, and

control the transceiver to receive the DL data based on the number of repetitions,

the second subframe is located after the first subframe.

17. A base station, BS, for transmitting downlink, DL, data in a wireless communication system, the BS comprising:

a transceiver; and

at least one processor coupled to the transceiver,

wherein the at least one processor is configured to:

controlling the transceiver to transmit information on the number of repetitions of the DL data repeatedly transmitted in at least one first Transmission Time Interval (TTI) included in a first subframe and at least one second TTI included in a second subframe, and

control the transceiver to transmit the DL data based on the number of repetitions,

the second subframe is located after the first subframe.